fossil

Fossil bivalve shell

Likely a fossilized oyster or other marine bivalve; exact genus is indeterminate from the image

AI-generated identification · may be incorrect

Cream to tan, flattened shell with radiating/concentric growth lines and possible mineral replacement. Original shell material is commonly calcite or aragonite; Mohs hardness about 3–4, dull to slightly silky luster, low cleavage, and specific gravity roughly 2.6–2.8.

Identified August 28, 2026More fossil →

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Physical properties

Formation & geological history

Formed as a marine mollusk shell, then buried in sediment and partially mineralized or preserved during diagenesis. Age cannot be determined visually; comparable specimens range from Paleozoic to Recent fossil-bearing strata.

Uses & applications

Primarily a teaching, display, and collecting specimen; fossil shell material may also be polished for décor, but it has little industrial value.

Geological facts

The growth bands record episodic shell growth and environmental changes. Oyster-like fossils commonly preserve irregular, thickened shells adapted to attachment on seafloors.

Field identification & locations

Look for bilateral shell symmetry, a hinge or beak, layered growth lines, and sediment infill; acid fizz would support carbonate composition but may damage it. Common in marine limestone and coastal sedimentary deposits worldwide.